USPS Information

Installation

USPS Approved and Ready

CBU’s are Pre-approved

Pre-approved by the USPS, cluster mailboxes are considered the industry standard when it comes to outdoor, centralized mail delivery.

Installation Location

If you are involved in a new construction development, you have probably already consulted or will consult with your local postmaster regarding the placement (location) of your CBU. If not, we recommend it.

Master Lock Installation

After installing the CBU, follow-up with your local post office and the USPS will install their master lock for the main access door. Note: the USPS provides the master lock and only they have the keys to it.

Five Year Warranty

All cluster box units (CBUs) sold on LowPriceClusterMailboxes.com come with a Five (5) Year Warranty.

Florence Manufacturing provides a five (5) year Warranty on its products from the date of purchase from an Authorized Florence Dealer (i.e., LowPriceClusterMailboxes.com). For more info, refer to the Auth-Florence Warranty sheet.

Likewise, Salsbury Industries covers defects in material and workmanship if reported in writing to them within five (5) years of the delivery date for CBUs. Refer to the Salsbury Warranty sheet for more details.

New USPS Standard

Obsolete: NDCBUs are no longer permitted for replacement or new installations

New CBUs accommodate both mail and packages while providing greater security.

Developed and approved by the USPS in 2005, the new cluster box unit specification (right image) became the standard for all manufacturers and replaces both the outdated Neighborhood Delivery Collection Box Unit (NDCBU) and the “E” series CBU.

While the original NDCBU introduced convenience for residents and letter carriers alike, it is no longer permitted for replacement or new installations. These outdated units fall into disrepair as they age and are, in many cases, quite dilapidated. The newer 2005 specifications boast a thoroughly tested design that provides better security and durability over time.

CBU High-Security Standards

All CBUs are designed to deter mail theft attempts using the following features:

All units are made of high grade, industrial, aircraft-quality aluminum.

On the outside of the unit, there are no removable fasteners. This prevents tampering.

The cabinet is made using high-precision robotic welding.

The CBU uses a sloped roof for water run-off and a drip-edge in the front to protect the individual slots from rainwater.

The master-loading door has a vertical bridge with an overlap that eliminates the gap between the two master-loading doors -- in other words, there are no pry-points on the unit.

Heavy-duty, zinc-plated cam locks are tamper proof and latch through the aluminum frame for added security.

The outgoing mail slot uses a sloping hood to prevent a person from reaching in with their hand.

The aluminum, anti-fish comb deters thieves from reaching into the slot with coat hangers or other prying tools.

Don’t need USPS delivery? Convert to private use.

If you don’t need USPS delivery and you intend to use the CBU for private use (where a company or organization will need access to open the master door for delivery), then you need the Postal to Private Conversion Kit, which can be purchased via the dropdown options section of any CBU.

Under the Option labeled “Will the USPS be delivering to this mailbox?”, select “No, this box is for private use…”. Private delivery CBUs are typical where mail delivery is handled by private distribution within the company or organization.

Lead Times

All orders ship directly from the factory floor to ensure the quickest available delivery.

LowPriceClusterMailboxes.com takes delivery dates and deadlines seriously. We update our lead time projections frequently in an effort to provide you with the most accurate projections. Currently, we estimate the following lead time:

Standard - Usually ships in 3 business days Custom - Usually ships in 1 to 2 weeks

When you select standard numbering (e.g, 1-8, 1P & 2P) for the CBU doors, the mailbox usually ships in 1 to 3 weeks.

When you select custom number plates or engraving, the CBU will usually ship in 3 weeks.

Customize Your Door ID Layout

Custom Layouts can be selected from the dropdown option labeled Door ID Layout.

You can customize the layout to suit your needs.

To ensure a custom layout is processed correctly, we ask that you complete this layout form after completing your purchase.

Door ID Options

Decals: All CBUs come standard with silver adhesive decals 1.5 inches high by 1.75 inches wide. Black lettering can contain up to five characters per decal.

Engraving: Custom engraving utilizes the USPS Standard US Block font with up to 12 characters per line. This ¾ inch high engraving may be created with or without one of two color fill options (white or black).

Note: CBUs selected with custom decals or engraving usually ship in three (3) weeks. We cannot rush orders for units purchased with custom numbering.

Optional Anchor Bolts (for New Concrete Installations only)

If you need anchor bolts for your CBU installation, add them from the dropdown options above the Add to Cart button.

Question: How do I know if I need anchor bolts?

Answer: The CBU anchor bolts, nuts, and/or vandal proof nuts for pedestal installation are specifically for installations where new concrete is being poured. For installing your CBU in existing concrete, see the Installation Walkthrough.*

The kit includes everything required to mount the CBU pedestal to newly poured concrete.

Vandal proof nuts can be purchased in addition to the standard nuts for added security.

*Note: actual measurements between bolts should be confirmed prior to installation. LowPriceClusterMailboxes.com is not liable for faulty installation due to inaccurate measurements.

Technical Specifications (Dimensions, etc.)

The top of the cluster mailbox (the crown) is 30.5 inches wide by 18.5 inches deep. The cluster box itself measures 30.5 inches wide by 16.75 inches deep by 48.25 inches high. Including the pedestal, the total unit height is 62 inches. For more detailed specifications, please view this Technical Drawing.

Color Options

The Auth-Florence 12 Door CBU is offered in four color variations while the Salsbury CBU is offered in six color variations. (Note: all green and white CBUs purchased on LowPriceClusterMailboxes.com are manufactured by Salsbury Industries.)

Sandstone is the most popular color option and is considered the new architectural standard. All finishes are powder-coated and corrosion-resistant. If you need to purchase a different color, you can view our selection of variations on the 12 Door CBU Category Page..

Design and Other Specifications

The 12-Door CBU includes two (2) fully integrated parcel lockers and a matching pedestal. One additional compartment is labeled "Outgoing Mail" and includes a weather protection flap and an 12 in. W x 3 in. H mail slot.

The CBU also features individually numbered mail compartments and a mail carrier access door for USPS provided master arrow lock.The unit itself is constructed of high-grade, heavy-duty, aircraft aluminum while the hardware is constructed of stainless steel. All CBUs on LowPriceClusterMailboxes.com are manufactured here in the USA.

Wide Tenant Boxes Accommodate Larger Envelopes and Magazines

Shown above: the 12 Door CBU Tenant Box (3 in. high)

Shown above: the 13 Door CBU Tenant Box (4 - ¾ in. high)

The Cluster Box Unit’s tenant compartment size is known as a 4C Horizontal mailbox, which is the current USPS Standard for centralized mail delivery. Under 4C regulations, the tenant boxes are wider so that all mail, including larger envelopes and magazines, can be delivered flat without any folding. There is also enough room in each tenant box for small-sized parcels.

Integrated Parcel Lockers

Among the many benefits of the CBU are the integrated parcel lockers for package delivery. If you receive a parcel, the Postal Carrier will conveniently leave the key to the parcel locker in your mailbox so that you can retrieve your package.

Security Tip: Once you enter the key and open the parcel locker the key cannot be removed. This is by design so that only the postal carrier can remove the parcel locker key. See video explanation below:

The matching CBU Pedestal - Easy Installation

*Disclaimer: the CBU anchor bolts, nuts, and/or vandal proof nuts for pedestal installation are specifically for installations where new concrete is being poured. Actual measurements between bolts should be confirmed prior to installation. LowPriceClusterMailboxes.com is not liable for faulty installation due to inaccurate measurements.

All cluster mailboxes include an easy-to-install pedestal. The CBU Pedestal is constructed of heavy-duty, corrosion-resistant aluminum. Cluster mailboxes can be mounted on the included pedestal (or a base of your choice provided it meets USPS height specifications).

The pedestal comes with the needed stainless steel hardware for 1) mounting the pedestal to the cluster box and 2) mounting the unit to the concrete slab (using standard bolts). If you need to purchase anchor bolts for installation prior to pouring the concrete slab,* you can add these via the dropdown options above the Add to Cart button.

Heavy-Duty Cam Lock

Every tenant door on the Cluster Box Unit features a stainless steel heavy-duty five-pin cylinder cam lock with a dust and rain shield, along with three (3) keys. This simple yet effective locking mechanism provides the needed security to keep your mail safe until you retrieve it.

If you ever need to replace one of the cam locks, the process is very straightforward. Watch the video below to see how you can replace one of these locks within minutes.

Opening the Master Doors & Locating Your Keys

Cluster Box Units (CBUs) are accessed from the front through two (2) easy-to-open master door panels.

Watch the video to see how to open the master doors and locate your keys (hint: the keys are taped to the inside of your box and are usually inside one of the parcel lockers).

See the corresponding video for more details.

Installation Walkthrough

Here we go over the basics of installing your cluster box into existing concrete. If you plan to install your CBU into new concrete, please see our Installation Manual below.

Note: we recommend you watch the video at the bottom of this section to get an idea of the installation process.

The Pedestal

When you open up the carton for the pedestal, you have a gasket and a template also. Follow the steps below to install your CBU pedestal into the concrete pad:

Locate the center of the pad, put the mounting template down, and then start drilling your holes (using the template).

Drill down four and a half inches with a half-inch drill bit.

Make sure the surface is clear of rocks and debris.

Once the area is clean, place the gasket down on the concrete (this serves as a barrier between the cement and the pedestal).

Now place the pedestal on top of the gasket. If it's not level, you can add washers to the uneven side.

Once the pedestal is level, you can place your anchors, which are four and a quarter inches long by one-half inch wide.

Place the anchors into the holes and torque the bolts down until they're tight using a socket wrench (you can also use an impact wrench to tighten the bolts).

Once you've tightened the bolts, double check that the pedestal is level.

The Cluster Box

Upon receiving the boxes, open them up to make sure there's no damage. Two people should place the box on the pedestal stand: one person can hold the box while the other person fastens it to the pedestal.

To fasten the box:

Inside the box, there will be access plates in the parcel locker(s). Go ahead and slide those out.

This will allow you to access the hardware to secure the box to the pedestal.

Place the washer on the bolt, followed by the nut. Do this to all four top bolts.

Ratchet the nuts with a nine-sixteenths (9/16) socket wrench.

Once these bolts are tight, return the access plates you removed from the parcel locker(s) in step one to cover the hardware.

Once complete, close up the box. Now, you will need to contact the post office to send someone to install their arrow locks for USPS access. The postman will install one arrow lock in the outgoing mail slot, and one in each parcel locker.

Installation Manual

Looking for a different document? See our full list of printable PDFs.

Who has a USPS License to manufacture CBUs?

Auth-Florence was founded in 1934 while Salsbury Industries began in 1936. Both have the exclusive license from the USPS to manufacture Cluster Box Units (CBUs) in the USA. CBUs from both manufacturers are relatively identical in both design and quality.

Where are they different?

Pricing - Salsbury Industries CBUs tend to have higher prices.

Lead times - Florence CBUs typically ship in 1-3 weeks while Salsbury CBUs tend to ship quicker in about 3-5 business days.

Finishes - Florence offers CBUs in four architectural finishes: Sandstone, Postal Grey, Bronze, and Black. Salsbury offers these four finishes as well as White and Green.

Options - While Auth-Florence CBUs can be purchased without pedestals (reducing the price), the Salsbury CBU can only be purchased with the included pedestal.

While pricing, lead time, finishes, and options are similar, they are not the same between the factories.

For example, sometimes Salsbury ships CBUs faster than Florence (or vice versa). Also, the manufacturer controls their own pricing, so often one brand may cost more than the other.

Lowpriceclustermailboxes has you covered. We keep it simple. We sell you the CBU from the manufacturer that is the cheapest and we give you transparent, up-to-date lead times once your order is placed.

What types of customers purchase Cluster Mailboxes?

Over the past nine years, we have serviced all types of properties. CBUs are commonly installed at the following:

Apartment Complexes

Homeowners Associations

Municipalities

Universities

Commercial Developments

Small Businesses

We are proud to supply CBUs to some of the nation’s most respected cities and companies.

CBUs - A Comprehensive Comparison

Florence & Salsbury USPS Approved Cluster Box Units

Pre-configured units include built-in parcel lockers and outgoing mail collection for added convenience to be used alone or in large groupings to accommodate every project need.

Below we list each pre-configured model number along with its associated manufacturer. Refer to the table below for detailed specs.

Outdoor Parcel Lockers - A Comprehensive Comparison

Florence & Salsbury USPS Approved Outdoor Parcel Lockers

Industry unique package delivery systems with key trapping locks can be used alone or with your CBU installation for better convenience. Below we list the available parcel lockers by both Auth-Florence and Salsbury Industries.

Auth-Florence USPS Approved Parcel Lockers

Salsbury Industries USPS Approved Parcel Lockers

Auth-Florence is the Sole Source Supplier to the USPS, meaning they are the only manufacturer authorized to supply cluster box units, outdoor parcel lockers, replacement pedestals, and parts directly to the USPS.

Auth-Florence is also the only company to manufacture the 1590-T2 Parcel Locker with Four (4) instead of Two (2) Parcel Locker doors.

Decorative Accessories - Comprehensive Comparison

Vogue™ Decorative Cluster Mailbox Accessories

These fashionable, snap-together toppers and pedestals put the final touch on your neighborhood or office cluster mailboxes. Choose from either the Classic or Traditional Styles below. Click the image to view the decorative configuration of your choice.

Regency™ Decorative Cluster Mailbox Accessories

Compare the Salsbury Regency CBU to the Florence Traditional Style shown above. Click on an image below to view more details on a specific configuration. The table below breaks down each decorative CBU’s specs.

CBU Care and Cleaning

You can use a soft cloth dampened with any mild detergent or a properly diluted biodegradable, water-based cleaner (e.g., Simple Green) to clean the surface of all clear aluminum or powder coated commercial mailboxes.

Basic cleaning

Wipe off the surface from top to bottom to avoid run-down.

Avoid using abrasives, which can damage the mailbox surface.

Rinse with plain water and dry the surface.

Avoid cleaning during extreme temperature conditions.

Advanced cleaning

To varying extents depending on the color, you may be able to remove some spray paint or marker applied graffiti from your CBU’s exterior by using a stronger cleaner like Krud Kutter or a mild petroleum-based solvent like mineral spirits.

Test a small, less noticeable area on the CBU first, a few seconds at a time. Do not allow the chemical cleaner to remain on the surface for an indefinite period, as this could damage the CBU’s exterior coating.

Remove any residue using a mild cleaner, and then rinse with plain water.

Cleaning your CBU hardware

If a mailbox lock or door mechanism becomes clogged with ice due to extreme winter conditions, the lock manufacturer suggests using Tri-Flow Superior Lubricant Aerosol.

Spray this lubricant directly into the keyhole and onto the key.

Slide the key in and out of the lock several times to spread the lubricant.

Do not apply too much product, as a small amount is sufficient.

Wipe off any excess lubricant from the lock and key.

Benefits of the CBU

The benefits of centralized mail delivery:

1. Value - It costs less to install per resident than individual curbside mailboxes. Also, mail delivery can often begin even before residences are occupied.

2. Community - CBUs can help build stronger neighbor relationships and trust as residents meet and talk while retrieving their mail.

Outdoor Parcel Lockers - A Comprehensive Comparison

Florence & Salsbury USPS Approved Outdoor Parcel Lockers

Industry unique package delivery systems with key trapping locks can be used alone or with your CBU installation for better convenience. Below we list the available parcel lockers by both Auth-Florence and Salsbury Industries.

Auth-Florence USPS Approved Parcel Lockers

Salsbury Industries USPS Approved Parcel Lockers

Auth-Florence is the Sole Source Supplier to the USPS, meaning they are the only manufacturer authorized to supply cluster box units, outdoor parcel lockers, replacement pedestals, and parts directly to the USPS.

Auth-Florence is also the only company to manufacture the 1590-T2 Parcel Locker with Four (4) instead of Two (2) Parcel Locker doors.

Decorative Accessories - Comprehensive Comparison

Vogue™ Decorative Cluster Mailbox Accessories

These fashionable, snap-together toppers and pedestals put the final touch on your neighborhood or office cluster mailboxes. Choose from either the Classic or Traditional Styles below. Click the image to view the decorative configuration of your choice.

Regency™ Decorative Cluster Mailbox Accessories

Compare the Salsbury Regency CBU to the Florence Traditional Style shown above. Click on an image below to view more details on a specific configuration. The table below breaks down each decorative CBU’s specs.